Tomorrow marks the second anniversary of the violent demise of Osama bin Laden. His death provided a measure of justice, yet recent events offer a chilling reminder of how the fanatical ideology and methodology he embodied remains.

The question is how to counter this violent religious extremism.

Here is one answer: Support religious freedom abroad.

The negative relation between extremism and freedom is clear. Studies show that while countries that protect religious freedom are more peaceful and stable than those that do not, nations that trample on this freedom provide fertile ground for war and terror and radical movements.

Indeed, of the four countries — Afghanistan, Saudi Arabia, Sudan, and Pakistan — that hosted bin Laden during his notorious life, each is an incubator of violent religious extremism, and all have perpetrated or tolerated repeated religious freedom violations.

In December 2012, the Australia-based Institute for Economics and Peace released a ranking of countries based on the number of terrorist attacks between 2002 and 2011. Seven of them — Iraq, Pakistan, Afghanistan, India, Somalia, Nigeria, and Russia — are either among the Tier 1 nations listed by the U.S. Commission on International Religious Freedom for designation as the world’s worst abusers or our Tier 2 list of serious religious-freedom violators.

Why is there a correlation between a lack of freedom and the presence of violent religious extremism?

First, when governments enforce laws — such as blasphemy-like codes — that stifle religious freedom, they embolden extremists to commit violence against perceived transgressors. In Pakistan, such codes fuel extremist violence against Christians and Ahmadi Muslims.

Second, when governments repress religious freedom or fail to protect it, they drive some into the arms of radical religious groups and movements. Russia’s repression of Muslims in the name of fighting the extremist views of some has produced violent extremism in others.

And finally, governments that crack down on everyone’s freedom in the name of fighting extremists also strengthen the extremists by weakening their more moderate, but less resilient, competition. Under President Mubarak’s rule, Egypt ended up strengthening the Salafists while weakening their more liberal opposition.

Taken in reverse, a government that abandons repression for freedom creates a true marketplace of ideas, forcing extremists to compete for hearts and minds with others.

In the end, in our post-9/11 world, there is no better way to defeat terrorism than by persuading people to reject the extremist ideologies that support it. Religious freedom is a powerful and effective tool to counter violent religious extremism and prevent the rise of future bin Ladens.

Katrina Lantos Swett, chair of the U.S. Commission on International Religious Freedom, lives in New Hampshire.